SIP Testing with FreeSWITCH

SIP Tes(ng w/ FreeSWITCH ClueCon, August 2013

Moisés Silva <[email protected]> Manager, So?ware Engineering

About Sangoma

•  Industry pioneer with over 25 years of experience in communicaIons hardware and so?ware

•  Publicly traded company since 2000 –  TSXV: STC

•  One of the most financially healthy companies in our industry –  Growing, Profitable, Cash on the Balance Sheet, No Debt

•  Mid-‐market sized firm with just under 100 staff in all global territories –  Offices in Canada (Toronto), US (CA, NJ), EU (UK & Holland), APAC

(India), CALA (Miami) •  World wide customer base

–  Selling direct to carriers and OEMs –  Selling to the enterprise through a network of distribuIon partners

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Sangoma Technologies -‐ © 2013

Broad Line of Great Products

•  Voice Telephony Boards –  Analog/digital/hybrid, WAN, ADSL

•  Session border controllers •  Microso? Lync •  VoIP Gateways

–  NetBorder SIP to TDM –  SS7 to SIP

•  So?ware ApplicaIons –  NetBorder Express, Call Progress

Analyzer… •  Transcoding (boards/appliances) •  Fiber connecIvity (STM1) •  Wireless products (GSM)

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Agenda

•  TesIng Overview

•  FuncIonality Tests

•  Load Tests

•  Security Tests

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Overview

•  I know, SIP tesIng can be scary

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Overview

•  TesIng complex systems requires detailed engineering and deep knowledge of OSes, wide range of protocols, hardware, etc

•  Not everyone likes doing it, it is not glamorous work …

•  But … It’s developer’s responsibility to test, not customer’s … shocking!

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Overview

•  Lots of open source tools out there that can be used for tesIng: •  Sipp •  Sipsak •  Sipvicious •  Voiper •  FreeSWITCH •  Asterisk

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Overview

•  Commercial tools as well •  IXLoad from Ixia •  SIP Hammer from Empirix

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Overview

•  FreeSWITCH can be used to test other systems •  Generate calls with full RTP wide array of codecs •  Support for IPv4/IPv6, TLS, SRTP, STUN, ICE etc •  Flexible programmable logic via XML, Python etc •  Originate/terminate T.38 faxing •  Originate/terminate SIP/TDM calls (and others) •  Easy to hook up modules to test media or signaling:

•  Example: tone_detect, mod_bert, fs_test

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Func(onality Tests

FuncIonality Tests

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Func(onality Tests

•  Verify expected SIP behaviors

•  REFER actually places a new call to given desInaIon •  183 with SDP actually bridges media •  4/5XX responses hang up or retry a call •  REGISTER creates an AOR in your DB •  … And you can go crazy with Presence tests …

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Func(onality Tests

•  IdenIfy your most important funcIonality

•  Execute manual tests, take traces (pcap/wireshark)

•  Write test scenarios for them

•  Automate them! (Python/Ruby/PERL scripIng)

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SIPp

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SIPp

•  FreeSWITCH Wiki SIPP Quote

“IF YOU DO NOT UNDERSTAND HOW TO STRESS TEST PROPERLY THEN DON'T BOTHER Using SIPp is part dark art, part voodoo, part Santeria. YOU HAVE BEEN WARNED”

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SIPp

•  Low-‐level SIP funcIonality & performance test tool

•  Not super user-‐friendly, errors can go unnoIced

•  Requires a firm grasp on SIP (requests, responses, transacIons, dialogs)

•  Flow logic is XML-‐based

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SIPp

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SIPp

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SIPp

•  <send>, <recv>, <pause>, <exec>, rinse & repeat •  <send> sends raw SIP messages

•  <recv> indicates you are expecIng a SIP response or request

•  <pause> waits some milliseconds

•  <exec> Can be used to play a pcap (and other stuff)

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SIPp

•  <send> takes care of re-‐transmissions if “retrans” awribute is used

•  <recv> blocks if non-‐opIonal

•  <exec> playing a file is non-‐blocking (surprising if you know FreeSWITCH/Asterisk playback)

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SIPp

•  More complex scenarios can be created with condiIonal branching

•  Use staIsIcal branching to add some variety to your scenarios

•  <pause> can be done using different distribuIon models such as normal, exponenIal, pareto, etc

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SIPp

•  Subtle mistakes can go unnoIced (no media)

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SIPp

•  Use [media_port] tag, do not hard-‐code ports in the SDP

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SIPp

•  Make sure you use –rtp_echo

•  Make sure you insert a <pause> a?er playing a pcap and make sure the pcap is long enough

•  For load tests raise your process limits (ulimit –a for details)

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SIPp

•  AutomaIng creaIon of SIPp scenarios out of pcap captures:

•  Sippie •  hwp://sourceforge.net/projects/sippie/

•  Sniff2sipp •  hwp://svnview.digium.com/svn/sniff2sipp/

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SIPSak

•  Mostly useful for flood tests

•  Much simpler/smaller than sipp, but less control

•  Easily used for RFC4475 tesIng (SIP Torture)

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FreeSWITCH

•  You can create SIP flows indirectly using FreeSWITCH applicaIons

•  No direct/raw SIP access, but possible through FreeSWITCH channel variables

•  Logic programmable in XML, Python, LUA etc

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FreeSWITCH

•  Use ESL originate to send INVITEs

•  fs_test Python script mimics some SIPp opIons •  hwps://github.com/moises-‐silva/fs_test

•  Control INVITE SIP headers through “sip_h_” originate variables

•  Send REFER with “deflect” applicaIon

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FreeSWITCH

•  Send 180 with “ring_ready”

•  Send 183 with “pre_answer”

•  Send 200 with “answer”

•  Send 3XX with “redirect”

•  Send 4XX/5XX/6XX with “respond”

•  Send BYE with “hangup”

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FreeSWITCH

•  G.711 media test / checking can be accomplished using mod_bert or tone_detect •  hwps://github.com/moises-‐silva/freeswitch/tree/mod_bert

•  Calls failing the media test are hung up with MEDIA_TIMEOUT reason

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Load Tests

Load Tests

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Load Tests

•  Load tesIng can be a fine art

•  Be careful and define tesIng scope •  OS (Linux, Windows, 64/32 bit, OS packages versions) •  Media features (RTP/SRTP, UDPTL, Codec) •  Signaling Features (TLS, PRACK, Presence, T.38) •  Hardware environment (CPU, Memory, PCI/PCIx, HD) •  Network environment (TCP/UDP/Ethernet se|ngs)

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Load Tests

•  Performance can vary widely when changing just a few environment characterisIcs, be sure to test a?er each change

•  Record your findings (ie: use CacI)

•  Do no underesImate non-‐call-‐related load •  RegistraIons, Presence, MWI, etc

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Load Tests

•  Measure your network performance / throughput

•  Use good cat6 ethernet cables! •  Use Iperf

•  hwps://code.google.com/p/iperf/

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Load Tests

•  Launching iperf server

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Load Tests

•  Launching iperf client

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Load Tests

•  Do not forget to verify with bwm-‐ng

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Iperf server bandwidth

Iperf client bandwidth

Load Tests

•  Slight payload change (iperf –l 172) causes significant performance difference

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Iperf server bandwidth

Iperf client bandwidth

Security Tests

Security Tests

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Security Tests

•  Sipvicious •  Voiper

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SipVicious

•  Sipvicious is handy to test your fail2ban rules

•  Use svwar.py and svcrack.py to trigger your fail2ban

•  Verify the host was blocked

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Voiper

•  Voiper is handy for fuzzy/vulnerability tesIng •  hwp://voiper.sourceforge.net/

•  Whatever you do, do not click on the last link at that page (UnprotectedHex)

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Voiper

•  python fuzzer.py -‐f SIPInviteCommonFuzzer -‐i 192.168.168.1 -‐p 5060 -‐a sessions/scen1 -‐c 0

•  Tons of messages like this on FreeSWITCH:

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Voiper

•  Note fail2ban can hardly help here (if at all)

•  SoluIon is report malformed packets via events and possibly block hosts sending excess of malformed traffic

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QUESTIONS

Contact Us

•  Sangoma Technologies 100 Renfrew Drive, Suite 100 Markham, Ontario L3R 9R6 Canada

•  Website hwp://www.sangoma.com/

•  Telephone +1 905 474 1990 x2 (for Sales)

•  Email [email protected]


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THANK YOU

SIP Testing with FreeSWITCH

Technology

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